A conventional locking mechanism of foldable golf carts principally contains a gripping portion (11) disposed on one side of a handle bar (1) of a golf cart. As shown in FIG. 1, the gripping portion extends inwardly to form a stop portion (12). A spring (13) is disposed between the stop portion (12) and the handle bar (1) to provide elastic forces. The elastic forces help the gripping portion (11) catch the upper portion of the support bar (2) to reach a ready-to-use state. Although the conventional locking mechanism can obtain a coupling effect, such a connection is not reliable and it might come apart when the golf cart is dragged on green. In addition, when users want to disconnect the engagement, they need to press the stop portion (12) toward the handle bar (1), which is not the way that people can apply forces with maximum efficiency. To make the cart change from a collapsed state to a developed state, users must press the stop portion (12) to make the gripping portion (11) move outwards first, and then catching the support bar is possible. Such an operation brings inconvenience to users.
Based on the above description, the primary object of the invention is to provide an improved locking mechanism that employs a retainer cooperated with an engagement element provided on the upper portion of the support post of a golf art to give a stable engagement and to provide convenience in use. Now the detailed structure and other features of the invention will become more readily apparent from the following detailed description of the preferred embodiment thereof when taken in conjunction with the accompanying drawings.